## $can is the canvas displaying the main graph and $can_1 is the controller canvas...

  $can_1->configure(-bandColor => 'orange');
  $can_1->CanvasBind('<Button-1>'               => sub {$can_1->CanvasFocus; $can_1->rubberBand(0)});
  $can_1->CanvasBind('<B1-Motion>'       => sub {$can_1->rubberBand(1)});
  $can_1->CanvasBind('<ButtonRelease-1>' => sub 
{
my @box = $can_1->rubberBand(2);
$can->viewArea(@box) 
});